In situ removal of Cephalexin by supported liquid membrane with strip dispersion

Abstract

Cephalexin is an important and widely used semi-synthetic antibiotic. Cephalexin is traditionally produced by a 10-step chemical synthesis. An enzymatic synthesis for Cephalexin has been developed, and offers several advantages over the classical route. 7-Amino-3-desacetoxicephalosporanic acid and d-phenylglycine amide were used as initial substrates for the enzymatic synthesis of Cephalexin with liquid penicillin G acylase. In situ extraction was achieved with a supported liquid membrane (SLM) with strip dispersion system that used commercially available hollow fiber modules and the carrier Aliquat 336. The maximum yield of Cephalexin was increased from 32% to 42% when in situ removal was conducted using two hollow-fiber modules and an organic membrane solution containing 10 wt% Aliquat 336. Enzyme stability experiments were preformed and showed that the organic membrane solution did not significantly deactivate the enzyme. The final recovery of Cephalexin from aqueous stripping solutions was achieved using complexing agents. The combination of SLM and complexation can prevent enzyme deactivation, which commonly occurs when complexation is conducted in enzymatic reaction mixtures.